Do IQ Tests Help To
Identify The Best Performers?

By Dr. Dennis Garlick

We all know
IQ tests. Love them or loathe them, they are still often a part of
assessment in the workplace. Performing well on an IQ test can be
the difference between getting hired or not, or getting that
promotion. But this represents a danger to businesses as well.
Critical decisions are being made based on tests that measure
underlying constructs that are not well understood. How much value
should be placed on performance on an IQ test? Only by understanding
what IQ tests measure, can their appropriateness be determined.

What Do IQ Tests
Measure? At their core, many
intelligence tests measure the ability to “understand”. Take word
analogy problems like Kitten is to Cat as Puppy is to _____. Solving
this problem involves understanding the relationship that is in
common between Kitten and Cat, and Puppy and Dog. Solving number
series like 3, 6, 9, 12, _____ involve understanding the general
pattern of the numbers and then applying this general pattern to
determine the next number in the sequence. In short, performing well
on tests like these involve understanding general principles that
can be applied across different situations.

Think of a “bright”
or “smart” person in the office. You know that they will be able to
understand most ideas or concepts that you explain to them. Often,
they need very little training, and can generalize their knowledge
from one situation to another. They don’t need to be given specific
instructions for every task. Instead, training will consist of a few
abstract goals, and then they will employ different actions in
different situations to flexibly attain those goals.

When assessment
tests are given to different people, it is often found that the some
are consistently good at understanding. This can be true even when
the situations are quite different, like the word analogy and number
series problems given above. People who do well at the word analogy
problems also tend to do well at the number series problems. How the
human brain is able to do this has been one of the key questions
that psychology has faced. Statistics have shown that people who
perform well on these types of items also tend to perform well in
job situations that involve understanding. This is what makes IQ
tests useful.

Recent Advances in
the Brain Sciences: When we hear that
someone has a high IQ, it is tempting to think that their brain has
some “magical” ability to understand or solve any problem. However,
it is found that understanding in adulthood is due to the
connections between the neurons. But it is not simply a case of
having more neural connections. In fact, the opposite is true:
people with higher IQs will actually have fewer connections! Having
fewer connections means that irrelevant information can be filtered
out, and this enables commonalities to be seen across situations.

The brain gets
fewer connections through childhood experience. The connections are
gradually pruned over childhood in response to experience. In other
words, the ability to understand is due to a learning process.
Experience with relevant abstractions in childhood leads to the
ability to understand those abstractions in adulthood. Some people’s
brains are better at this process than others, and this leads to
them having a higher IQ.

IQ vs. Experience
In The Workplace: But what if a
high-IQ person has not had relevant childhood experience in a
domain? While they may score high on an IQ test, their brain will
not have the right connections to understand the domain. This means
that they will need to memorize appropriate steps and procedures,
just like someone with a lower IQ who also lacks relevant
experience.

Conversely, what if
someone with a lower IQ does have relevant childhood
experience? Imagine if someone with a lower IQ grew up selling goods
on a street corner and interacting with customers, while someone
with a higher IQ who spent all of their childhood at home studying.
In this case, the person with the lower IQ is likely to perform
better in sales and marketing positions and relating to customers.
While the higher IQ child may have had greater potential, their lack
of experience prevented them from turning this potential into
ability. In these cases, the IQ test does not help to identify the
best performers.

Implications for
Assessment: What this tells us
is that IQ is not a direct measure of the ability to understand.
When a job requires skills such as those involved in schoolwork, a
higher-IQ person may perform better on evaluation. However, in other
situations, using assessments that mirror on-the-job tasks are
likely to be the most accurate for gauging specific workplace
requirements and future potential. So while IQ tests can be
effective, care needs to be taken with using them. Only in some
situations are they helpful.